Embodiments in accordance with the present invention relate to a suspension for testing characteristics of a magnetic head slider which is used in a magnetic disk drive.
A magnetic head slider is used for magnetically writing or reading data on a magnetic disk. Before being used in a magnetic disk drive, the magnetic head slider is tested for flying characteristic with a magnetic disk rotated and for electromagnetic transducing characteristic about writing and reading data on a magnetic disk. The magnetic head slider is attached to a suspension so as to be able to fly over the magnetic disk. A magnetic head formed on a slider is connected to an external characteristic tester via an electric connection terminal and a circuit pattern.
Conventionally, the magnetic head slider is fixed to gimbals of the suspension with adhesive. Ultrasonic bonding or soldering is used for an electric connection terminal of the magnetic head to the suspension's circuit pattern to form a head gimbal assembly (HGA). The HGA is attached to a characteristic tester for characteristic test. The characteristic test tests the flying characteristic and the writing and reading characteristic over a rotating magnetic disk.
The HGA-based characteristic test uses an HGA formed by using adhesive and ultrasonic bonding or soldering. When an HGA is determined to be faulty, it is discarded entirely. For a high recording density magnetic disk unit in the future, the HGA uses highly-functional parts such as a suspension mounted with a complicated circuit patter and an actuator for positioning control of the magnetic head. Discarding a faulty HGA wastes costs for these parts and assembly works.
The wasted costs may be effectively decreased by removing the magnetic head slider and the adhesive from the HGA determined to be faulty as a result of the characteristic test and reusing remaining parts such as the suspension. However, there is a possibility of increasing costs by damaging parts or increasing man-hours due to removal of the adhesive.
Patent document 1 (JP-A No. 312373/1999) describes the HGA using the plate member having the mechanism capable of attaching and detaching the slider. The HGA is bonded to the gimbals with an adhesive between gimbals and the slider of the suspension mounted on a magnetic disk drive, not the suspension for magnetic head slider characteristic test. Patent document 1 describes the detachable mechanisms including the electromagnetic detachable mechanism using a magnetic layer for the slider rear side opposite to the gimbals, the vacuum adsorption detachable mechanism with a dimple formed in the plate member, and the detachable mechanism using a stable two-position shape member or a shape memory alloy.
The suspension for magnetic head slider needs to be reusable by removing a slider determined to be faulty according to a magnetic head slider characteristic test and mounting another slider. For this purpose, there is a need for the mechanism that can facilitate mounting and dismounting a slider, prevent an increase in costs of damaged parts or increased man-hours for a mounting and dismounting work, and hold the slider so as not to be removed due to a shock caused from handling during the characteristic test and the manufacturing process.
The HGA described in Patent document 1 (JP-A No. 312373/1999) can be used for the suspension for magnetic head slider characteristic test. However, the electromagnetic mechanism needs a magnetic layer formed on the slider surface opposite to the suspension and a circuit for mounting and dismounting control. The electromagnetic mechanism may increase manufacturing costs due to a complicated manufacturing process. The vacuum adsorption mechanism may decrease a holding force due to air leakage from the depressurized adsorption portion or thermal expansion of air caused by the ambient temperature. The mechanism using the stable two-position shape member or the shape memory alloy is subject to limitation on the use of materials, temperatures, and the like.